1.5 mm Galvanised Steel Sheet Galvanized Sheet Metal Roofing Gi Plain Sheet

GI Sheet Material Types
The commonly used galvanized steel grades are:

Commercial Sheet (CQ);
Forming Steel;
GI Sheet for Structural Use (HSLA);
Deep Drawing Steel Sheet (DDQ);
Extra Deep Drawing Steel (EDDS), etc.

How to Calculate GI Sheet Weight?
The GI sheet weight follows the calculation formula: W= Thickness (mm) * Width (m) * Length (m) * 7.85 (Density of steel = 7.85 kg/m3) + zinc layer weight

Taking gauge 18 GI sheets (G90) for example, the thickness is about 1.31 mm. The zinc layer is about 275 g/m2. So the galvanized sheet weight per square meter is about 10.58 kg. You can roughly get the weight. If your galvanized sheet is 0.7 mm in thickness, 1.2 m in width, and 2.5 m in length, the weight is about 16.5 kg/piece (0.7*1.2*2.5). If you order 50 tons, there will be about 3,000 pieces. You can estimate how many GI sheets are needed for your project easily.
Hot-dip Galvanized Steel Sheet
Hot-dip galvanized sheet is made by immersing the steel sheet in a molten zinc bath at about 500 °C to attach a zinc layer to the surface. This is the continuous galvanizing process. It will form a protective zinc layer on the surface so that it has good paint adhesion and weldability. It is the most widely used and cost-effective method to prolong the service life of steel sheets. .
Electro-galvanized Steel Sheet
Electro-galvanizing, also known as cold galvanizing, uses electrolysis to form a uniform and dense layer on the surface of the metal. The anti-corrosion zinc layer can protect steel parts from oxidation corrosion. Also, it can meet decorative purposes. But the zinc layer of the electro-galvanizing steel sheet is only 5-30 g/m2. So its corrosion resistance is not as good as hot-dip galvanized sheets.

Difference Between Hot-Dip and Electro-galvanized Steel Sheets
Anti-corrosion
The zinc coating thickness is one of the most important factors matters corrosion resistance. The greater the zinc layer thickness, the better the corrosion resistance. Generally, the thickness of hot-dip zinc coating is more than 30 g/m2, or even as high as 600 g/m2. While the electro-galvanized zinc layer is only 5~30 g/m2 thick. So the former steel sheet is much more corrosion resistant than the latter one. At Wanzhi Steel, the maximum zinc layer is 275 g/m2 (z275 galvanized steel sheet).

Method of Operation
The hot-dip galvanized steel sheet is galvanized in a molten zinc bath at about 500 degrees, while the electro-galvanized steel sheet is processed at room temperature by electroplating or other methods. That's why electro-galvanizing also refers to the cold galvanizing process.
Surface Smoothness & Adhesion
The surface of the electro-galvanized steel sheet looks smoother than hot-dip galvanized sheets. But its adhesion is not as good as that of the hot-dip galvanized sheet. If you want only one side galvanized, you can choose the electroplating method. However, if adopting hot-dip galvanizing, both sides are coated with a zinc layer fully.
Types of GI Sheets
In terms of the manufacturing process, we divide it into hot-dip galvanized steel sheets and electro-galvanized steel sheets. Hot-dip galvanized sheet is mainly used in construction, home appliances, automobiles, light industry, and other industries. Below are more details for your reference.